1. Field of the Invention
The invention relates to a vehicle impact detection system, and more specifically, to a system for transmitting an impact to the side of a vehicle body.
2. Description of the Related Art
Vehicle occupant protection devices that have been used include a curtain airbag and a side airbag that detect an impact in the event of a side impact crash and then deploy between an occupant and the vehicle body.
The curtain airbag, the side airbag and the like are actuated in response to a command from an airbag ECU after load (deceleration) caused in the event of a side impact crash was detected by two impact sensors located in the side part of the vehicle body and in the center in the vehicle-width direction, and the impact was sensed by the airbag ECU.
Concerning an occupant protection device like the one mentioned above, however, the curtain and side airbags and the like might fail to be actuated even if the load is inputted from the outside in the vehicle-width direction in the event of a side impact crash (especially a collision with a pole). This is because an impact area is locally deformed due to small contact area between the impacted object (pole) and the vehicle body, and this local deformation of the impact area consumes impact energy, resulting in a failure to accurately transmit impact load to the impact sensors.
Given the above facts, a technology has been developed, in which a load-transmitting member is installed in an air dam (rocker molding), and the load inputted from the outside in the vehicle-width direction into the air dam in the even of a side impact crash is transmitted to impact sensors (Unexamined Japanese Patent Publication No. 2008-254702).
According to the publication, the load-transmitting member is fixed with a foam material in the air dam, and the load produced in the event of a side impact crash is transmitted from the load-transmitting member through a side sill to the impact sensor located in the side part of the vehicle body.
However, the transmission of the impact load to the impact sensor located in the center in the vehicle-width direction fails to be carried out as impact energy is consumed because of deformation in the side sill or the like. There is a possibility that an impact is not detected with proper timing by the impact sensor located in the center, and then that airbag deployment is delayed. This is an unfavorable situation.